1. Field of the Invention
The present invention relates to a light scanning apparatus, and an image forming apparatus including the light scanning apparatus.
2. Description of the Related Art
Hitherto, an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) includes a light scanning apparatus configured to emit a laser beam (hereinafter referred to as a light beam). The light scanning apparatus emits the light beam, which, is modulated in accordance with image information, and scans a uniformly charged surface of a photosensitive member (surface to be scanned) with the light beam, to thereby form an electrostatic latent image on the surface to be scanned. The electrostatic latent image is developed into a toner image by a developing device with developer (toner). The toner image is transferred and fixed onto a recording medium. In this manner, an image is formed on the recording medium.
The light scanning apparatus includes a semiconductor laser (light source), a rotary polygon mirror (deflecting member) configured to deflect the light beam emitted from the semiconductor laser, a motor (deflection scanning device) configured to rotate the rotary polygon mirror, and an imaging optical system configured to image the light beam onto the surface to be scanned. The imaging optical system includes optical elements such as an fθ lens and a reflecting mirror. The semiconductor laser, the rotary polygon mirror, the motor, and the imaging optical system are arranged in an optical box (housing) with high accuracy.
A power supply electric wire and a signal wire (communication wire) are electrically connected to an electric circuit board configured to drive the motor. The power supply electric wire and the signal wire (communication wire) are bundled into an electric wire bundle. The electric wire bundle is led out of the optical box. The electric wire bundle led out of the optical box is connected to an electric wire bundle of a main body of the image forming apparatus through intermediation of a connector.
However, foreign matters adhering onto the electric wire bundle may soil the optical elements inside the optical box. The electric wire bundle is formed of a plurality of electric wires bundled with a band so as not to come apart from each other. The operation of binding the plurality of electric wires is carried out manually, and thus the foreign matters such as sebum and fuzz generated from a person or clothes adhere onto a surface of the electric wire bundle. The plurality of electric wires are densely bundled into the electric wire bundle, and hence it is difficult to fully remove the foreign matters from the electric wire bundle as a matter of fact. Specifically, the electric wire bundle having even a small amount of the foreign matters adhering thereonto is arranged inside the optical box, and thus the foreign matters may adhere onto the optical elements in the vicinity of the electric wire bundle. When the foreign matters adhere onto the optical elements, the light beam is shaded (vignetted), resulting in optical scanning failure, and further, image failure.
Further, depending on a route of the electric wire bundle to be laid inside the optical box, it is sufficiently conceivable that the electric wire bundle blocks an optical path of the light beam.
In view of the above, in Japanese Patent No. 4171634, various electric wire bundles are caused to pass through double walls formed on both sides of the optical box of the light scanning apparatus. The various electric wire bundles need not be laid over a long distance in a space in which optical components of the light scanning apparatus are mounted. Therefore, the risk of soiling the optical components or shading the light beam is suppressed, which leads to an advantage in obtaining stable quality of the image formation. In this manner, it is desired that the route of the electric wire bundle to be laid inside the optical box be short to the extent possible and be arranged in a different space partitioned from the space in which the optical components are mounted.
In recent years, however, from the viewpoint of enhancing maintainability of the image forming apparatus, the light scanning apparatus is removably mounted to the main body of the image forming apparatus. Therefore, at the time of mounting the light scanning apparatus to the main body of the image forming apparatus, there is a problem in that the electric wire bundle led out of the light scanning apparatus is caught in the components of the main body, thereby obstructing the mounting.